<!DOCTYPE html>
<html>
<!-- Created by GNU Texinfo 7.1.1, https://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<!-- This file documents the use of the GNU compilers.

Copyright © 1988-2023 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below).  A copy of the license is included in the section entitled
"GNU Free Documentation License".

(a) The FSF's Front-Cover Text is:

A GNU Manual

(b) The FSF's Back-Cover Text is:

You have freedom to copy and modify this GNU Manual, like GNU
     software.  Copies published by the Free Software Foundation raise
     funds for GNU development. -->
<title>PDP-11 Options (Using the GNU Compiler Collection (GCC))</title>

<meta name="description" content="PDP-11 Options (Using the GNU Compiler Collection (GCC))">
<meta name="keywords" content="PDP-11 Options (Using the GNU Compiler Collection (GCC))">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta name="viewport" content="width=device-width,initial-scale=1">

<link href="index.html" rel="start" title="Top">
<link href="Indices.html" rel="index" title="Indices">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Submodel-Options.html" rel="up" title="Submodel Options">
<link href="PowerPC-Options.html" rel="next" title="PowerPC Options">
<link href="OpenRISC-Options.html" rel="prev" title="OpenRISC Options">
<style type="text/css">
<!--
a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em}
kbd.key {font-style: normal}
span:hover a.copiable-link {visibility: visible}
-->
</style>


</head>

<body lang="en_US">
<div class="subsection-level-extent" id="PDP_002d11-Options">
<div class="nav-panel">
<p>
Next: <a href="PowerPC-Options.html" accesskey="n" rel="next">PowerPC Options</a>, Previous: <a href="OpenRISC-Options.html" accesskey="p" rel="prev">OpenRISC Options</a>, Up: <a href="Submodel-Options.html" accesskey="u" rel="up">Machine-Dependent Options</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<h4 class="subsection" id="PDP_002d11-Options-1"><span>3.19.37 PDP-11 Options<a class="copiable-link" href="#PDP_002d11-Options-1"> &para;</a></span></h4>
<a class="index-entry-id" id="index-PDP_002d11-Options"></a>

<p>These options are defined for the PDP-11:
</p>
<dl class="table">
<dt><a id="index-mfpu-3"></a><span><code class="code">-mfpu</code><a class="copiable-link" href="#index-mfpu-3"> &para;</a></span></dt>
<dd><p>Use hardware FPP floating point.  This is the default.  (FIS floating
point on the PDP-11/40 is not supported.)  Implies -m45.
</p>
</dd>
<dt><a id="index-msoft_002dfloat-10"></a><span><code class="code">-msoft-float</code><a class="copiable-link" href="#index-msoft_002dfloat-10"> &para;</a></span></dt>
<dd><p>Do not use hardware floating point.
</p>
</dd>
<dt><a id="index-mac0"></a><span><code class="code">-mac0</code><a class="copiable-link" href="#index-mac0"> &para;</a></span></dt>
<dd><p>Return floating-point results in ac0 (fr0 in Unix assembler syntax).
</p>
</dd>
<dt><a id="index-mno_002dac0"></a><span><code class="code">-mno-ac0</code><a class="copiable-link" href="#index-mno_002dac0"> &para;</a></span></dt>
<dd><p>Return floating-point results in memory.  This is the default.
</p>
</dd>
<dt><a id="index-m40"></a><span><code class="code">-m40</code><a class="copiable-link" href="#index-m40"> &para;</a></span></dt>
<dd><p>Generate code for a PDP-11/40.  Implies -msoft-float -mno-split.
</p>
</dd>
<dt><a id="index-m45"></a><span><code class="code">-m45</code><a class="copiable-link" href="#index-m45"> &para;</a></span></dt>
<dd><p>Generate code for a PDP-11/45.  This is the default.
</p>
</dd>
<dt><a id="index-m10"></a><span><code class="code">-m10</code><a class="copiable-link" href="#index-m10"> &para;</a></span></dt>
<dd><p>Generate code for a PDP-11/10.  Implies -msoft-float -mno-split.
</p>
</dd>
<dt><a class="index-entry-id" id="index-mno_002dint32"></a>
<a id="index-mint16"></a><span><code class="code">-mint16</code><a class="copiable-link" href="#index-mint16"> &para;</a></span></dt>
<dt><code class="code">-mno-int32</code></dt>
<dd><p>Use 16-bit <code class="code">int</code>.  This is the default.
</p>
</dd>
<dt><a class="index-entry-id" id="index-mno_002dint16"></a>
<a id="index-mint32-1"></a><span><code class="code">-mint32</code><a class="copiable-link" href="#index-mint32-1"> &para;</a></span></dt>
<dt><code class="code">-mno-int16</code></dt>
<dd><p>Use 32-bit <code class="code">int</code>.
</p>
</dd>
<dt><a id="index-msplit"></a><span><code class="code">-msplit</code><a class="copiable-link" href="#index-msplit"> &para;</a></span></dt>
<dd><p>Target has split instruction and data space.  Implies -m45.
</p>
</dd>
<dt><a id="index-munix_002dasm"></a><span><code class="code">-munix-asm</code><a class="copiable-link" href="#index-munix_002dasm"> &para;</a></span></dt>
<dd><p>Use Unix assembler syntax.
</p>
</dd>
<dt><a id="index-mdec_002dasm"></a><span><code class="code">-mdec-asm</code><a class="copiable-link" href="#index-mdec_002dasm"> &para;</a></span></dt>
<dd><p>Use DEC assembler syntax.
</p>
</dd>
<dt><a id="index-mgnu_002dasm"></a><span><code class="code">-mgnu-asm</code><a class="copiable-link" href="#index-mgnu_002dasm"> &para;</a></span></dt>
<dd><p>Use GNU assembler syntax.  This is the default.
</p>
</dd>
<dt><a id="index-mlra-2"></a><span><code class="code">-mlra</code><a class="copiable-link" href="#index-mlra-2"> &para;</a></span></dt>
<dd><p>Use the new LRA register allocator.  By default, the old &ldquo;reload&rdquo;
allocator is used.
</p></dd>
</dl>

</div>
<hr>
<div class="nav-panel">
<p>
Next: <a href="PowerPC-Options.html">PowerPC Options</a>, Previous: <a href="OpenRISC-Options.html">OpenRISC Options</a>, Up: <a href="Submodel-Options.html">Machine-Dependent Options</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html" title="Index" rel="index">Index</a>]</p>
</div>



</body>
</html>
